This specification generally relates to training a machine learning model that predicts values of search engine ranking signals for resources that are indexed in an index database of a search system.
Online search engines generally rank resources in response to received search queries to present search results identifying resources that are responsive to the search query. Search engines generally present the search results in an order that is defined by the ranking. Search engines may rank the resources based on various factors, i.e., based on various search engine ranking signals, and using various ranking techniques.